The Assessment of Operative Results in Congenital Heart Disease by Intraoperative Indicator-Dilution Curves

Abstract

In 260 patients with intracardiac shunts, indicator-dilution curves were recorded immediately after corrective operations. In every patient, the effectiveness of the repair was also determined at late postoperative cardiac catheterization or necropsy. In 248 patients (96 per cent) the presence or absence of a shunt, determined from the intraoperative curves, was confirmed by the findings at postoperative study. The intraoperative curves were normal in 213 patients, 209 of whom had no residual communication at late evaluation; in four patients, the studies indicated initial complete correction followed by recurrence of the shunt. Abnormal intraoperative curves were recorded in 47 patients, eight of whom died. In 17 of the 39 surviving patients, postoperative catheterization revealed persistent residual shunts comparable in magnitude to those present before operation. Fourteen patients had residual shunts that did not necessitate reoperation, and in eight patients, shunts present at the conclusion of the operation were shown to close in the postoperative period. The study indicates that the recording of intraoperative indicator-dilution curves provides a reliable objective method for evaluating the effectiveness of operation in patients with circulatory shunts. If normal curves are recorded, no residual shunt may be expected in 98 per cent of patients, and postoperative catheterization may be unnecessary unless other hemodynamic data are required. If abnormal intraoperative curves are recorded, however, postoperative study is mandatory, since the shunt will persist in 80 per cent of patients, in many of whom a second operation will be indicated.